Every cell in your body contains 23 unique chromosomes. Each chromosome has 2 copies, total, 46. One copy is inherited from your mother, and another from dad. Since egg & sperm cells have only one copy of each chromosome, there is random chance of the maternal or paternal version of each one passed down to baby.
Many traits are also influenced by both genes and the environment, while your DNA plays a role, it can also differ depending on other factors such as nutrition. So we can’t know for sure how someone looks like just based on their genes alone!
Babies of African or Asian descent are often born with dark eyes. However, many Caucasian babies are born with blue or grey eyes that darken over time. This is because melanocytes, the cells that produce pigment in your eyes, are activated by light. When a newborn is exposed to light for the first time at birth, their melanocytes start producing a dark pigment called melanin, which takes several months to build up. Most babies reach their final color by the time they are 6 to 9 months old.
Like eye color, hair color is determined by melanin. Hair contains a form of melanin called eumelanin, which is dark brown in color. Lots of eumelanin = black or brown hair, while less eumelanin = blonde hair. Babies’ hair changes color or texture as they grow too. Hair color tends to darken in the first few months of life, then grow lighter during the toddler years, and then darken to a final shade by the age of 5.
Earlobe shape is controlled by 49 genes, so no shape is dominant. It's generally accepted that earlobes have no biological function. Did you know that people with uneven earlobes are rated as better leaders?
Sadly some babies born with dimples, later fade away as baby fat in cheeks disappear. Babies born without dimples can also develop them later in life! But if both parents have dimples, there’s a good chance that your baby will too!
Lactose intolerance can be a recessive trait, so you'll need to inherit this trait from both of your parents in order to experience it!